1. Field of the Invention
This invention relates generally to methods and apparatus for hydraulically transporting solids, and more particularly, but not by way of limitation, to an improved method and apparatus for forming a particulated solids-carrier liquid slurry and transporting it between first and second locations.
2. Description of the Prior Art
In the mining and transport of minerals such as coal, hydraulic transport methods and apparatus have heretofore been developed and used wherein the solids to be transported are particulated, combined with a carrier liquid, and the resulting slurry is pumped to a terminal location where the solids are separated from the carrier liquid. Generally, the apparatus heretofore utilized has included at least a solids accumulator, an open mixing tank or sump wherein the pumpable slurry is formed and one or more pumps for pumping the slurry. Such prior apparatus are generally bulky and cannot be operated in applications where head room is limited, e.g., in mining low thin coal seams. Further, since prior art apparatus have included open solids-carrier liquid mixing chambers, spillage of the carrier liquid and solids can occur when the flow of solids to be transported increases.
By the present invention, an improved method of forming a particulated solids-carrier liquid slurry and transporting it between locations is provided which is carried out in relatively simple low profile apparatus including a closed carrier liquid-slurry circuit which apparatus is particularly suitable for use in limited head room applications and which obviates spillage problems.
The method of the invention basically comprises the steps of flowing a continuous stream of carrier liquid to a first location at a constant flow rate, injecting the particulated solids to be transported directly into the carrier liquid at the first location so that a particulated solids-carrier liquid slurry is formed, pumping the solids-carrier liquid slurry to a second location, and controlling the rate at which the solids-carrier liquid slurry is pumped from the first location to the second location so that the pressure level of the carrier liquid at the first location is maintained at a predetermined level thereby facilitating the direct injection of the particulated solids thereinto. Apparatus for carrying out the method including a closed carrier liquid-slurry circuit is also provided by the invention.
It is, therefore, a general object of the present invention to provide an improved method and apparatus for hydraulically transporting solids.
A further object of the present invention is the provision of a method of hydraulically transporting particulated solids which can be carried out in a closed fluid circuit whereby spillage of the carrier liquid is minimized.
Another object of the present invention is the provision of a method of a hydraulically transporting particulated coal and simple economical apparatus for carrying out such method which can be utilized in thin coal seams and other locations where head room is limited.
Yet another object of the present invention is the provision of methods and apparatus for hydraulically transporting particulated solids wherein problems associated with plugging the transporting conduit due to too high a solids concentration or too low a slurry flow rate are generally obviated.
Other and further objects, features and advantages of the invention will be readily apparent to those skilled in the art upon a reading of the description of preferred embodiments which follows taken in conjunction with the accompanying drawings.